Spent the last week sorting out my boat that just went into the water. Something funny going on at the electrical panel.

When I switch on the breaker for the shower pump, my panel shows a jump to nearly 20 amps on the "draw" meter. This happens when the breaker is switched on. The pump is not running as there is an on/off switch in the head so there should be no draw at all. The normal draw when the pump runs is about 7 amps. The only breaker that acts this way is the one for the shower pump. Any ideas before I open up the panel and have a look? Thanks.

There is an increase of over 10 amps. The breaker doesn't trip because it's a 20 amp ( I think). I should have been a bit more exact. It just freaked me out to see the needle jump up like that. My fridge was running when I did this and it draws 4 amps. If I remember right the needle jumped to over 15 but under 20.

Certainly sounds like you may have a high resistance short on that circuit. Are you sure that you don't have something else connected to that breaker, as well as the sump pump? About the only way to determine what is happening is to trace your wiring, check all connections and the back of the switch to ensure you don't have any corrosion that is causing a short.

Good question, just reminded me that the fridge pump which has not been working for years and is a bit rusty, (actually it looks like a lump of rust) is on the same circuit. I'll look at that first when I go down tomorrow.

When my wife panics about something techincal, I always tell her to firstly calm down, think clearly, there is always a simple logical explanation.
The first thing I would do is find what the output of the breaker is definatly feeding.